Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to the air defence system, and more specifically, relates to a system and method for a distributed weapon to target engagement in a hierarchical military air defence scenario.

BACKGROUND
[0002] A lot of work in the field of air defence systems has been found in the literature to understand the process of threat evaluation and weapon assignment within the context of ground-based air defence systems referring to one of the papers titled “Threat evaluation and weapon assignment decision support: The paper aims to review the state of the art of this kind of threat evaluation and weapon assignment decision support process as it stands within the context of a ground-based air defence system (GBADS) at the turn of the twenty-first century. However, much of the contents of the paper may be generalized in an obvious manner to military environments other than a GBADS one.
[0003] A few existing works in the field of air defence systems have found that military air defence is the branch of forces which provides the defence to specified vulnerable areas/vulnerable points against air attacks using gunnery and/or surface to Air Guided Weapons (SAGW). An Air defence area is a specifically defined geographical area that includes objectives of possible enemy air attack and for which air defence must be provided. An air defence area may be subdivided into air defence sectors with their controlling units or control centres. So, there is a need for a method for a hierarchical air defence system consisting of various interconnected and interdependent units and distributed resources i.e., command & control centres, weapon systems like guns/missiles or other electronic active or passive warfare.
[0004] Computation of the quantum of threat or vulnerability from threatening aerial targets in air defence scenarios plays an important part while evaluating air defence situations. Computation of threat is the process of evaluating and quantifying the threat posed to an air or ground-based asset from a threatening air target. It forms the underlying logic to arrive at a decision to neutralize a hostile air threat. Globally decision support system in the C4I system has a threat assessment and weapon to target engagement entities as an integral part of the C4I system. Computation and assessment of threats or vulnerabilities in air defence scenarios is a very challenging and complex process. Prioritizing air threats requires a sound and healthy awareness of the air situation picture.
[0005] An example of such an air defence system is recited in a patent EP 1 029 216 B1 titled “A method for automatic weapon assignment”. This invention relates to automatic threat evaluation and weapons assignment systems, and more particularly to such a system which incorporates knowledge databases or expert system techniques in the solution. In this work, the defended area is also divided into defensive zones and each zone has to have their zone target table and allocated weapon database to be used for engaging a target.
[0006] Yet another example is recited in a paper titled “Threat evaluation and weapon assignment decision support. This paper aims to review the state of the art of this kind of threat evaluation and weapon assignment decision support process as it stands within the context of a ground-based air defence system (GBADS) at the turn of the twenty-first century.
[0007] However, the aforementioned patent suffers from limitations that do not follow a hierarchy of control centres following a top-down hierarchy of approach. In this patented work, each defensive zone is working in isolation maintaining its separate zone target table. A whole air situation picture is not available at any nodal zone centre cooperating with other zones. This causes defensive zones to assign a weapon to the target in a non-cooperative way that is multiple weapons may be assigned to the same target at the same time if the target appears in overlapping zones. Besides, referred patent does not specify the weapon selection criteria for a target at the zone level.
[0008] Therefore, it is desired to overcome the drawbacks, shortcomings, and limitations associated with existing solutions, and develop a unique method for calculating the weapon solution index at the lowest control centres where weapons are deployed to protect the asset in the 360-degree coverage area.

OBJECTS OF THE PRESENT DISCLOSURE
[0009] An object of the present disclosure relates, in general, to the air defence system, and more specifically, relates to a system and method for a distributed weapon to target engagement in a hierarchical military air defence scenario.
[0010] Another object of the present disclosure is to provide a system that provides military air defence to detect all aerial targets and neutralise the threat well away from the vulnerable area/point (VA/VP) by effective integration of all air defence weapon systems dedicated to protecting from ariel or airborne threatening targets.
[0011] Another object of the present disclosure is to provide a system that determines and passes down the track information of the threatening target to the most suitable and effective weapon system which can neutralize the target with maximum efficiency.
[0012] Another object of the present disclosure is to provide a system that enables and automates the complete process from target reception through vulnerability or threat determination to neutralization within an appreciable time limit.
[0013] Yet another object of the present disclosure is to determine the best available weapon among a number of deployed weapons for the protection of a particular asset or VA/VP lying in the area of responsibility at the respective lowest-level control centre.

SUMMARY
[0014] The present disclosure relates in general, to the air defence system, and more specifically, relates to a system and method for a distributed weapon to target engagement in a hierarchical military air defence scenario. The main objective of the present disclosure is to overcome the drawback, limitations, and shortcomings of the existing system and solution, by providing a method that covers both the aspect of threat or vulnerability calculation and weapon allocation in a military air defence scenario which may consist of a number of command-and-control centres with the distributed area of responsibility within which protecting weapon sections lie for the protection of defended assets and area.
[0015] In air command and control systems, post-detection, identification of targets, and prioritization of aerial threatening targets is a primary and important task. When an unknown target enters one’s territory, it is subjected to object identification techniques to determine its identity. Once its identity is established as a threat or hostile, it means this threatening object is about to inflict injury or damage to our defended assets e.g., geographically important areas or points, dams, bridges, important infrastructures etc., which are of paramount importance to one’s country. As the number of aerial threats increases manifold, there is a need to neutralize threats systematically before it can hurt or damage people or defended assets. To accomplish this task, a timely and dynamic calculation of threats posed to the assets from these threatening targets is required, so the present disclosure caters to this problem and gives a prioritized threat matrix for target-assets pairs. To evaluate the threat posed by a target on the defended asset, a range of parameters (e.g., proximity between target and asset, target heading/course, target speed, weapons range and their arcs etc.) have been considered in the air defence environment. Besides the calculation of vulnerability or threat matrix, there is a need for the determination of the suitable weapons deployed to track and neutralization of threatening targets before the threatening target can inflict injury or damage to the vulnerable or defended assets.
[0016] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0018] FIG. 1 illustrates an exemplary view of hierarchical control centres, in accordance with an embodiment of the present disclosure.
[0019] FIG. 2 illustrates an exemplary view of a block diagram of the hierarchical control centres, in accordance with an embodiment of the present disclosure.
[0020] FIG. 3 illustrates an exemplary view of the angle of intrusion w.r.t VA/VP or weapon location, in accordance with an embodiment of the present disclosure.
[0021] FIG. 4 illustrates an exemplary view of the primary arc of the weapon at the centre, in accordance with an embodiment of the present disclosure.
[0022] FIG. 5 illustrates an exemplary view of the bearings diagram, in accordance with an embodiment of the present disclosure.
[0023] FIG. 6 illustrates an exemplary flow chart of a method for distributed weapon to target engagement in hierarchical military air defence system, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0024] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0025] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0026] The present disclosure relates, in general, to the air defence system, and more specifically, relates to a system and method for a distributed weapon to target engagement in a hierarchical military air defence scenario. The proposed framework disclosed in the present disclosure overcomes the drawbacks, shortcomings, and limitations associated with the conventional framework providing a hierarchical framework of military air defence control systems or centres where at the highest level a controlling node is bestowed with all types of operational control entrusted with a larger area of responsibility. An efficient novel methodology for prioritizing and engaging ariel targets with the best possible weapon like anti-aircraft gun/missile systems lying at the lowest level with dedicated/marked areas of responsibility in the hierarchy has been envisaged and this process or methodology has been proven and supported by parametric evaluations with 360-degree point and area defence.
[0027] When two or more types of weapon systems are allotted for providing area/close defence it may be termed a composite defence. While planning the layout for a composite defence the layout for the weapon system with the longest maximum effective range would be planned first and thereafter shorter-range weapon systems may be deployed according to their planning considerations. The layout of long-range weapon systems may be weighted towards priority assets or exposed boundaries in the combat zone and the short-range weapon systems may be used to fill gaps, if any, in the overall layout at the lowest control centre controlling or using weapons sections. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0028] In an aspect, the system includes at least three control centres defining an uppermost level, middle level, and lowest level respectively in the hierarchy to maintain information pertaining to defended assets, and weapons present in area of responsibility (AOR). A tracker coupled to the at least three control centres and receives information of targets from a set of sensors periodically, the tracker configured to provide targets as input to the vulnerability computation process at the uppermost level for vulnerability computation of the targets, assign the computed target list by the resource allocation process located at the middle level to the lowest level and determine, upon receipt of the assigned targets list, by the weapon to target allocation process located at the lowest level, a suitable weapon among a number of deployed weapons of a weapon system for the protection of particular asset lying in the AOR at the respective lowest level.
[0029] In another aspect, the vulnerability computation process calculates vulnerability or threat from the target based on intent and proximity calculation from defended asset data. At the uppermost level, a controlling node is bestowed with all types of operational control entrusted with a larger area of responsibility. The resource allocation process assigns targets to the control centre at the lower level based on target-asset relationship in terms of vulnerability score. The targets assigned from the upper-level control centres are subjected for vulnerability computation followed by the resource allocation process to further assign or allocate targets to next lowest level control centres. The weapon to target allocation process determine suitable weapons which can be used to engage and neutralize a particular target effectively.
[0030] Moreover, the system is configured to determine and pass down the track information of the target to the most suitable and effective weapon system coupled to the control center at the lower level to neutralize the target with maximum efficiency. The weapons are deployed to protect the asset in 360-degree coverage area. Besides, the system comprises datastore that stores defended assets, location data, and area of responsibility (AOR) data of each control centres.
[0031] The advantages achieved by the system of the present disclosure can be clear from the embodiments provided herein. The system provides military air defence to detect all aerial targets and neutralise the threat well away from the vulnerable area/point (VA/VP) by effective integration of all air defence weapon systems dedicated to protecting from ariel or airborne threatening targets. The system determines and passes down the track information of the threatening target to the most suitable and effective weapon system which can neutralize the target with maximum efficiency. The system enables and automates the complete process from target reception through vulnerability or threat determination to neutralization within an appreciable time limit. Further, the present disclosure determines the best available weapon among a number of deployed weapons for the protection of a particular asset or VA/VP lying in the area of responsibility at the respective lowest-level control centre. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0032] FIG. 1 illustrates an exemplary view of hierarchical control centres, in accordance with an embodiment of the present disclosure.
[0033] Referring to FIG. 1, military air defence control system 100 (also referred to as system 100, herein) can include command and control centres which are connected by network backbones such as Ethernet or satellite communication-based network are disclosed. The system 100 can include at least three centers, where at least three centers can include the highest-level command & control centre 102, middle-level control centres 104 and lowest-level control centres 106.
[0034] In an embodiment, the highest-level command and control centre 102 includes the air defence battle in the tactical battle area is orchestrated from the highest-level command & control centre 102, which forms the uppermost level in the command, control and reporting system in the combat zone. At this level, there is a complete and updated air situation picture, it have means for air defence firing area promulgation, identification and threat assessment. It shall have information on all the weapons systems and defended assets or VA/VPs present in the system or its area of responsibility (AOR).
[0035] The weapons list at this level shall include weapons of all lowest-level control centres lying in its area of responsibility (AOR). This top-level control centre has the complete picture of all airborne targets detected by its long-range surveillance radars covering the total area of responsibility under all control centres under it.
[0036] The middle-level control centres 104 form the second level of automation. The capabilities at this level are enhanced to cater for a larger area of responsibility and also to ensure the lateral link to other sub-systems of the Command Control Communications and Intelligence (C3I) system. The middle level may normally control a range of six to nine lowest-level control centres and one to two surveillance radars to detect air targets. This level shall have the information of all the weapon systems and defended assets or VA/VPs present in its area of responsibility that is information of all weapons and defended assets VA/VPs lying under the direct control of all lowest control centres under this level.
[0037] The lowest level control centres 106 include the lowest level at the troop/battery level is the lowest command & control node in the hierarchy. It is linked to sensors and weapons. It receives air target data from air surveillance radar, synthesizes it, relates it to other parameters viz., weapon control orders, weapon location, identification etc., and initiates action against hostile aircraft by carrying out target designation. The lowest level control centre 106 controls a range of weapon fire units. This level needs inputs of weapons, sensors, weapon location and status, local air picture, identification, weapon assignment and control orders.
[0038] In an air defence scenario, the hierarchically distributed area responsibility for the protection of vulnerable area/vulnerable points (VA/VP) or may be called defended assets, there is a process of first calculating vulnerability or posed threat from the threatening targets and then systematically assigning those targets to the effective weapons system through the process of weapon solution generation. As both these processes are done in sequence, the process of dynamic vulnerability computation is explained first. Vulnerability matrix computations (VMC) are done at top-level and middle-level control centres which are hierarchically connected to the top-level or highest control centre.
[0039] At the top level, all the threatening tracks are considered for vulnerability computation and finally prioritized vulnerability matrix consisting of rows of the target to VA/VP pairs is computed from this matrix targets are assigned to owner middle-level control centres 104 which are the parent to lowest level control centre 106 responsible for protecting threatened VA/VP from the assigned threatening target. Similarly, vulnerability computation is done at the middle level on the assigned targets only and targets are assigned further to lower-level control centre 106 based on the ownership of the threatened VA/VP. Once the information about the assigned targets list is received at the lowest control centre 106, the process of evaluating weapon assignment solution or weapon solution generation starts and then further targets are assigned to weapon systems possessing surface-to-air guided missiles or gunneries.
[0040] FIG. 2 illustrates an exemplary view of the block diagram of the hierarchical control centres, in accordance with an embodiment of the present disclosure.
[0041] The process like the vulnerability computation model, resource allocation process and weapon-to-target allocation method is depicted in FIG. 2. The resource allocation process resides at the highest and middle-level control centre and the weapon-to-target allocation method is applicable to the lowest level command & control centre 106. From the block diagram, it is clear that there are two major processes viz., vulnerability computation with resource allocation and weapon to target allocation process or method. Both processes work on real-time fused confirmed tracks received from the tracker and fixed data or information about the position of defended assets, and characteristics of weapons deployed.
[0042] Dynamic Vulnerability Matrix Computation (VMC)– Applicable at the highest and middle level control centres.
[0043] The vulnerability computation process takes place at the highest level say command & control centre 102 and middle level control centre in the framework, process following data as described below:
[0044] Receive the confirmed targets or fused air situation awareness information from the tracker (202-1, 202-2) and store them locally. VMC expects that confirmed tracks having identified hostility may contain mapping information for tracks for all tracks received from higher nodes with respect to tracking numbers at lower nodes i.e., tracks are available at all control centres with unique identification numbers. As the tracker provides target information consisting of the targets position, altitude, course, speed and its identity, use the target kinematics & positional data from track information.
[0045] Consider and process the defended assets or VA/VPs and own weapons and their deployed positional information like latitude and longitude information along with their performance characteristics stored in the data store.
[0046] Take the priority of VA/VP (say on a scale from 1 to 10) mentioned as part of VA/VP data. The higher the value so higher the priority of VA/VP.
[0047] It shall compute the threat or vulnerability index for all applicable VA/VPs based on some parameters calculation and assignment of calculated weights for parameters under consideration
[0048] Other relevant data includes the area of responsibility (AOR), locations of control centres etc., all are stored in the data store at each control centre as depicted in the block diagram in FIG.2.
[0049] The components of the block diagram include:
[0050] The tracker 202-1 provides target data as input to the vulnerability computation process, resource allocation process at highest and middle-level control centres and weapon-to-target allocation method at lowest control centres. The tracker 202-1 is an application which resides at all the control centres and receives information on airborne targets data from attached deployed sensors/radars periodically and manages the targets' information.
[0051] The tracker 202-1 periodically generates the confirmed tracks identified with unique identification numbers. These confirmed tracks are also subjected to an identification process which results in the tracks with their identified hostility such as hostile or threatening targets. The tracker 202-1 provides threatening targets information consisting of the targets position, its altitude, course, speed and its identity as input to the proposed method consisting of a series of steps for calculating threat or vulnerability index and weapon solution generation for a particular threatening target.
[0052] The data stores 204 at all levels of control, data-store 204 provides and keeps the non-real-time data like information about defended assets or VA/VP, Area of Responsibility (AOR) data of each control centres, and locations data of all control centres. The data-store 204 also stores and provides data about weapons deployed and their locations, real-time weapons status data and their performance characteristics information. A vulnerable area (VA) may be any specified geographical area that may be circular or a polygon having an area of more than one square kilometer. An area having an area less than or equal to one square kilometer is termed as a vulnerable point (VP).
[0053] The vulnerability computation model is applicable at the highest and middle-level control centres. It is the model for vulnerability computation which calculates vulnerability or threat from the threatening target based on intent and proximity calculation that is its proximity from the defended asset or VA/VP. The resource allocation process is responsible for assigning targets to lower control centre 106 based on target-VA/VP relationship in terms of vulnerability score or degree of threat the target poses to a particular VA/VP or asset.
[0054] At lower control centres 106, only targets assigned from higher control centres 102 are subjected to further vulnerability computation followed by the resource allocation process to further assign or allocate targets to the next lower or lowest level control centres 106. The weapon-to-target allocation method is applicable at lowest control centres only: This method is responsible for determining suitable weapons which can be used to engage and neutralize a particular target effectively assigned from upper control centres. This process determines the suitability of weapons based on their primary arc, and their performance characteristics like maximum effective range in the case of a gun and cross-over range in the case of a missile. The weapons solution carrying the information of the target is sent to attached weapon systems or sections controlling the guns or missiles. The vulnerability matrix computations (VMC) are done at top-level and middle-level control centres which are hierarchically connected to the top-level or highest control centre.
[0055] FIG. 3 illustrates an exemplary view of the angle of intrusion 300 w.r.t VA/VP or weapon location, in accordance with an embodiment of the present disclosure.
• Calculation of angle of intrusion:
[0056] Based on the heading of the aircraft, calculate the angle of intrusion with respect to bearing between the target and VA/VP.
[0057] Let, Ɵ = Bearing of VA/VP from target T w.r.t. True North
Angle of Vector T from T (i.e., Target) to V (i.e., VA/VP) w.r.t. true north
Vector TV from T (i.e., Target) to V (i.e., VA/VP) w.r.t. true north.
Let αi be the Angle of Intrusion, then
αi =abs (Bearing of VAVP w.r.t. Target – Heading of the Target)
αi =abs (Ɵ – Ɵc) deg
• Calculation of ‘TimeToReach’ with respect to each VA/VP and corresponding weightage assignment based on defined slots:
[0058] Effective distance is computed between VA/VP centre and Target’s current position. The computed distance between VA/VP and the target may be slant range if target is at a height (h). Range of weapon system of VA/VP may be used to calculate effective target distance. Let De be called Effective Distance and Vs be called speed of the target, then
[0059] De = abs (Target Distance from VA/VP – Δ)
Where, for the case of artillery
Δ= (Effective Range of own artillery) Km
OR
Δ= (Cross Over Range of own munition) in Km
(for the case of Munition/Missile)
[0060] The formula Effective Distance (De)/ (Speed* Cos (αi)) be the time taken by the target to reach VA/VP. The formula (Speed* Cos (αi)) is the velocity component of the target velocity along the bearing line joining target to VA/VP. Based on experimental results, a target can be considered Approacher if angle of intrusion is less than 80 degrees, otherwise target is considered as Receder.
• TimeToReachWeightage Calculation: Its value lies between one and zero. Higher is the value of TimeToReach, then lesser shall be the value of weightage for time to reach. Based on the slots of time to react, assign Time-Weightage to the time. The maximum Weightage Factor (W.F) is 1. Weightage allocation for TimeToReach on 100-point scale could be taken as sub-score STTR (say a value of 90).
[0061] Let TimeToReach (i.e., Effective Distance / (Speed* Cos (αi)) be the time taken by the target to reach VA/VP, then,
Let Nt be the number of time intervals.
Let size of the interval be Isize = (MaxValueofTime)/Nt;
The MaxValueofTime is the assumed threshold value of time to be taken by the target to reach the defended asset beyond which time value, the threat may be considered negligible.
[0062] For each interval Kth (value ranges from 1…Nt), check for;
IF ((Isize * Kth- Isize +1) <= TimeToReach <= (Isize * Kth))
TimeToReachWeightage = [1.0- (1/Nt) * (Kth-1)]
IF (TimeToReach > MaxValueofTime)
TimeToReachWeightage =0
• Priority of VA/VP (1-10): The maximum priority weightage is 1. The weightage allocation on 100-point scale could be taken as sub-score SP (say a value of 10). Priority Weightage is proportional to priority of the defended asset or VA/VP. Higher is the value of priority, higher is the weightage for priority.
Priority Weightage= (Priority of VA/VP)/10;
[0063] Now Final Threat or Vulnerability Index (Vi) for threatened VA/VP from the threatening target can be calculated as:
Vi = STTR * TimeToReachWeightage + SP * Priority Weightage
[0064] At the top level control centre, a complete set of targets will be considered for vulnerability computation. It is essential to generate and update and prioritize. Vulnerability Matrix (VM) is based on a vulnerability index dynamically as long as a threatening track exists in system. Vi takes the value on 100-point scale. The higher is the value of Vi, so higher the threat from the target.
[0065] Priority (1= least priority,10 = highest priority) of the defended asset or VA/VP.
[0066] From this prioritized threat/vulnerability computation matrix, the threatening tracks are assigned by resource allocation (RA process) either automatically or manually by the operator to lower-level control centres 106 having the direct or indirect responsibility of protecting VA/VPs being threatened by assigned threatening targets. The resource allocation process assigns threatening targets to the affiliated lower-level control centre 106 of the threatened asset or VA/VP.
[0067] This assignment of tracks from higher level nodes/control centre to lower level to weapons level allows systematic allocation of threatening tracks and the final responsibility for neutralizing the targets by the best lowest level control centre having ownerships of attached sections of weapons consisting of either artillery (short range non-maneuvering projectile) or munitions (long-range maneuvering projectile) or both at the same weapon section.
[0068] Weapon Solution Generation (WSG)– Applicable at lowest level Control Centres directly attached to weapon sections.
[0069] Weapon solution generation is basically a process which enables the reactive assignment of suitable weapons to threatening targets assigned from upper levels in hierarchy. WSG process takes place at the lowest control centre in the hierarchy. This process has the following steps as discussed below.
• Receive and process confirmed and identified tracks data from tracker, weapon details and their location details along with characteristics or performance data from respective weapons data store.
• At lowest level only assigned (by resource allocation from higher nodes) set of targets will be considered for WSG.
• Under lowest level node or control centre, there shall have either Artillery or Munition or both at the weapons section attached with the centre.
• It shall compute the solution index for all applicable weapons in sections attached to the control centre based on following factors as described below.
[0070] Parameters or factors calculation for Artillery (short range non maneuvering projectile) OR Munitions (long range maneuvering projectile or missile) deployed at sections under the control of any lowest control centre.
(a) Serviceability State of Artillery and Munition:
If Artillery or Munition system is functional, then the weightage factor is 1 else weightage factor is zero, that is,
ServiceabilityWeightageFactor =1 if functional,
OR
ServiceabilityWeightageFactor =0 if under service or repair.
(b) Calculation of angle of intrusion: Referring to FIG. 3 based on the heading of aircraft, calculate angle of intrusion with respect weapon location instead of VA/VP.
(c) Calculation of ‘TimeToReach’ with respect to each Weapon location and corresponding weightage assignment based on defined slots:
[0071] The maximum Weightage Factor (W.F) for time to reach is 1. Weightage allocation for TimeToReach on 100-point scale could be taken as subscore STTR (say a value of 90).
[0072] Position of target within firing arc of artillery or munition/missile.
[0073] I. The maximum weightage factor (W.F.) is 1. Weightage allocation for position of target within firing arc of artillery (short range projectile) or munition (long range maneuvering projectile or missile) on 100-point scale could be taken as sub-score SPOS (say a value of 75).
[0074] II. Compute bearing of target (T) w.r.t., weapon position (W). Let it be called ƟWT degree.
[0075] III. Primary arc of the weapon 400 is the sector within which it can engage targets effectively. Let RA and LA be right of arc and left of primary arc of gunnery or munition/missile as shown in FIG. 4 below:
[0076] Let α be the half of angular spread of weapon arcs, such that (Assuming that angular spread (2α) would not be more than 180Ɵ)
[0077] CASE 1: When (LARA), then
[0080] α= ((360-(LA-RA))/2) deg. (Refer to fig. 4)
[0081] Now, when threatening target bearing (ƟWT) with respect to own weapon position is within the arcs, then
[0082] CASE 2: When (LARA), then
(For Δ, refer to fig 5, indicates angular range around centre of Arc)
If ((RA-2α) < 0Ɵ) then
RA-2α = (360+ (RA-2α)).
If ((RA-α) < 0Ɵ) then
RA-α = (360+ (RA-α))
If ((RA – (α+Δ)) <0Ɵ), then
RA – (α+Δ) = (360 + (RA – (α+Δ))
If ((RA – (α-Δ)) <0Ɵ), then
RA – (α-Δ) = (360 + (RA – (α-Δ))
Now,
1.1 If ((RA-2α) <= ƟWT <= (RA – (α+Δ))
PositionOfArcWeightage = 0.75
1.2 If ((RA-(α+Δ)) < ƟWT <= (RA-(α-Δ)))
PositionOfArcWeightage = 1.0
1.3 If ((RA-(α-Δ)) <ƟWT <= RA)
PositionOfArcWeightage = 0.75
[0084] FIG. 5 illustrates an exemplary view of bearings diagram 500, in accordance with an embodiment of the present disclosure. The bearings diagram (target vs. weapon at the centre of the figure).
[0085] Now the formulas to compute the position of arc weightage when track bearing (ƟWT) is outside the weapons arcs, are explained as below; (Note: Applicable for (LA>RA) or (LA 360Ɵ)
ƟBB = (ƟBB – 360) Ɵ
else if (ƟBB < 0Ɵ)
[0087] ƟBB = (ƟBB + 360) Ɵ
Let β be the angle computed as follows
β = ƟBB - RA ( refer to fig. 5 )
Now, if (β > 360Ɵ)
β = (β – 360) Ɵ
else if (β < 0Ɵ)
β = (β + 360) Ɵ
[0088] Now let Ɵi be the angle or bearing computed as follows: (refer to fig. 5)
Ɵi = (RA + i * β/4), where i is number starting from 1 through 8.
Now, if (Ɵi >= 360Ɵ)
Ɵi = (Ɵi – 360) Ɵ
else if (Ɵi < 0Ɵ)
Ɵi = (Ɵi + 360) Ɵ
[0089] Now the formula for position of arc weightage is explained below;
When (Ɵi < ƟWT < Ɵi+1) and Ɵi+1< 360Ɵ
Let WA = 0.75 and WB = (0.75 – 0.25) then,
PositionOfArcWeightage = (WA – y * WB /4)
where, y = i when (1 <=i <=4) or
y = 9 - i when (5 <=i <=8)
4.2 And when Ɵi < ƟWT < Ɵi+1, where
Ɵi+1 = > 360Ɵ and Ɵi < 360Ɵ
[0090] Angular interval shall be broken into two intervals as given below:
Ɵi < ƟWT < 0Ɵ, and 0Ɵ < ƟWT < Ɵi+1 (example – Ɵ7 < 360Ɵ and Ɵ8> 360Ɵ in fig. 5)
PositionOfArcWeightage for this interval shall remain the same.
[0091] Final Solution Index can be calculated as:
(a) In case of gunnery (short range projectile) weapon system:
[0092] For mobile weapon section, it is to ignore position of arc weightage and give 100 % weightage to time_to_reach weightage, so final solution for mobile section will be
[0093] Solution Index (At lowest level) = (100 * TimeToReachWeightage + 0* PositionOfArcWeightage) *(ServiceabilityWeightageFactor)
[0094] And, for static weapon section, final weapon solution index for static section will be same as before,
[0095] Solution Index (At lowest level) = (STTR * TimeToReachWeightage + SPOS PositionOfArcWeightage) * (ServiceabilityWeightageFactor)
[0096] Note: All the weightages used in the above formula have already described above. STTR and SPOS are sub-scores for time to reach and position of arc on 100 point scale respectively as explained previously.
[0097] In case of munition (long range manoeuvring projectile) weapon system:
Minimum distance between own munition position and extrapolated path of target on basis of speed and heading:
I. Compute the shortest distance to the extrapolated path of target
from the weapon position. Let it be called Ds.
II. Maximum weightage factor is 1.
III. Weightage Factor (W.F.) for different slots of shortest distance
is taken and used in computation of threat calculation at lowest
level of node.
CROSS_RANGE is a crossover range of missile in
consideration.
If (CROSS_RANGE > Shortest Distance)
WeightageFactorForMissile =LOW
If (CROSS_RANGE == Shortest Distance)
WeightageFactorForMissile =MEDIUM
If (CROSS_RANGE < Shortest Distance)
WeightageFactorForMissile =HIGH
[0098] For mobile weapon section, similarly ignore position of arc weightage and give 100 % weightage to time_to_reach weightage, so final weapon solution index for mobile section will be
[0099] Solution Index (At lowest level) = (100 * TimeToReachWeightage + 0*PositionOfArcWeightage) * (WeightageFactorForMissile *ServiceabilityWeightageFactor)
[00100] And, for static weapon section, final weapon solution index for static section will be same as before,
[00101] Solution Index (At lowest level) = (STTR * TimeToReachWeightage + SPOS * PositionOfArcWeightage) *(WeightageFactorForMissile * ServiceabilityWeightageFactor
[00102] The weapon solution index reflects the suitability and effectiveness of using the concerned weapon. It is a comparative degree or index with which a particular weapon either gunnery or munitions at the section can be used for target destruction as compared to other weapons deployed at different sections under the same control centre.
[00103] FIG. 6 illustrates an exemplary flow chart of a method for the distributed weapons to target engagement in a hierarchical military air defence system, in accordance with an embodiment of the present disclosure.
[00104] Referring to FIG. 6, at block 602 at least three control centres defining an uppermost level, middle level and the lowest level in the hierarchy are provided to maintain information pertaining to defended assets, and weapons present in the area of responsibility (AOR).
[00105] At block 604, the tracker is provided as input to the vulnerability computation process at the uppermost level for vulnerability computation of the targets, the tracker is coupled to at least three control centres and receives information on the targets from a set of sensors periodically.
[00106] At block 606, the computed target list is assigned by the resource allocation process at the middle level to the lowest level and at block 608, determining, upon receipt of the assigned targets list, by the weapon to target allocation process at the lowest level, a suitable weapon among a number of deployed weapons of a weapon system for the protection of particular asset lying in the AOR at the respective lowest level.
[00107] Thus, the present invention overcomes the drawbacks, shortcomings, and limitations associated with existing solutions, and provides a system that provides military air defence to detect all aerial targets and neutralise the threat well away from the vulnerable area/point (VA/VP) by effective integration of all air defence weapon systems dedicated to protecting from ariel or airborne threatening targets. The system determines and passes down the track information of the threatening target to the most suitable and effective weapon system which can neutralize the target with maximum efficiency. The system enables and automates the complete process from target reception through vulnerability or threat determination to neutralization within an appreciable time limit. The system determines the best available weapon among a number of deployed weapons for the protection of a particular asset or VA/VP lying in the area of responsibility at the respective lowest-level control centre.
[00108] It will be apparent to those skilled in the art that the system 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT INVENTION
[00109] The present invention provides a system that provides military air defence to detect all aerial targets and neutralise the threat well away from the vulnerable area/point (VA/VP) by effective integration of all air defence weapon systems dedicated to protecting from ariel or airborne threatening targets.
[00110] The present invention provides a system that determines and passes down the track information of the threatening target to the most suitable and effective weapon system which can neutralize the target with maximum efficiency.
[00111] The present invention provides a system that enables and automates the complete process from target reception through vulnerability or threat determination to neutralization within an appreciable time limit.
[00112] The present invention provides to determine the best available weapon among a number of deployed weapons for the protection of a particular asset or VA/VP lying in the area of responsibility at the respective lowest-level control centre.

, Claims:1. A system (100) for distributed weapon to target engagement, the system comprising:
at least three control centres (102, 104, 106) defining an uppermost level, middle level and lowest level respectively in the hierarchy to maintain information pertaining to defended assets, and weapons present in area of responsibility (AOR);
a tracker (202-1) coupled to the at least three control centres and receives information of targets from a set of sensors periodically, the tracker configured to:
provide targets as input to the vulnerability computation process at the uppermost level for vulnerability computation of the targets;
assign the computed target list by the resource allocation process located at the middle level to the lowest level; and
determine, upon receipt of the assigned targets list, by the weapon to target allocation process located at the lowest level, a suitable weapon among a number of deployed weapons of a weapon system for the protection of particular asset lying in the AOR at the respective lowest level.
2. The system as claimed in claim 1, wherein the vulnerability computation process calculates vulnerability or threat from the target based on intent and proximity calculation from defended asset data.
3. The system as claimed in claim 1, wherein at the uppermost level a controlling node is bestowed with all types of operational control entrusted with a larger area of responsibility.
4. The system as claimed in claim 1, wherein the resource allocation process assigns targets to the control centre at the lower level based on target-asset relationship in terms of vulnerability score.
5. The system as claimed in claim 1, wherein the targets assigned from the upper level control centres are subjected for vulnerability computation followed by the resource allocation process to further assign or allocate targets to next lowest level control centres.
6. The system as claimed in claim 1, wherein the weapon to target allocation process determine suitable weapons which can be used to engage and neutralize a particular target effectively
7. The system as claimed in claim 1, wherein the system is configured to determine and pass down the track information of the target to the most suitable and effective weapon system coupled to the control center at the lower level to neutralize the target with maximum efficiency.
8. The system as claimed in claim 1, wherein the weapons are deployed to protect the asset in 360-degree coverage area
9. The system as claimed in claim 1, wherein the system comprises datastore that stores defended assets, location data, and area of responsibility (AOR) data of each control centres.
10. A method (600) for distributed weapon to target engagement in hierarchical military air defence system, the method comprising:
providing (602) at least three control centres defining an uppermost level, middle level and lowest level in the hierarchy to maintain information pertaining to defended assets, and weapons present in area of responsibility (AOR);
providing (604), by a tracker, input to the vulnerability computation process at the uppermost level for vulnerability computation of the targets, the tracker coupled to the at least three control centres and receives information of the targets from a set of sensors periodically;
assigning (606) the computed target list by the resource allocation process at the middle level to the lowest level; and

determining (608), upon receipt of the assigned targets list, by the weapon to target allocation process at the lowest level, a suitable weapon among a number of deployed weapons of a weapon system for the protection of particular asset lying in the AOR at the respective lowest level.